XKCD 687
# Dimensional analysis
#
# https://xkcd.com/687/
let core_pressure = 3.5 million atmospheres
let prius_milage = 50 miles per gallon
let min_width_channel = 21 miles
# Make sure that the result is dimensionless:
let r: Scalar =
planck_energy / core_pressure × prius_milage / min_width_channel
print("{r} ≈ π ?")
Source: https://xkcd.com/687/